Purification of organic silicon polymer

Abstract

An organic silicon polymer is purified by washing at least once a solution of an organic silicon polymer with aqueous hydrochloric acid having a concentration of at least 0.001 N, and washing the solution at least twice with ultrapure water having a resistivity of at least 10 MΩ/cm. Metal impurities can be removed from the organic silicon polymer to a sufficient level for use as electronic material without detracting from the polymer's own properties.

What is claimed is: 
     
       1. A method for purifying an organic silicon polymer, comprising the steps of: washing at least once a solution of an organic silicon polymer with aqueous hydrochloric acid having a concentration of at least 0.001 N, and   washing the solution at least twice with ultrapure water having a resistivity of at least 10 MΩ/cm, thereby removing metal impurities from the organic silicon polymer.   
     
     
       2. The method of claim 1 wherein said organic silicon polymer is a solvent-soluble polysilane having a linear or branched structure. 
     
     
       3. The method of claim 1 wherein said organic silicon polymer is a solvent-soluble polycarbosilane containing a silicon-to-silicon bond and having a linear or branched structure. 
     
     
       4. The method of claim 1 wherein said organic silicon polymer is a polysilane or polycarbosilane resulting from the Wurtz process. 
     
     
       5. The method of claim 1 wherein said organic silicon polymer is obtained from a ring opening polymerization process or an anionic polymerization process. 
     
     
       6. The method of claim 1 wherein said organic silicon polymer has an average molecular weight of 500 to 5000. 
     
     
       7. The method of claim 1 wherein said organic silicon polymer is contained in a solvent in a concentration of 5 to 40% by weight. 
     
     
       8. The method of claim 7 wherein the concentration of said organic silicon polymer in the solvent is 10 to 20% by weight. 
     
     
       9. The method of claim 1 wherein the concentration of aqueous hydrochloric acid is 0.1 to 2 N. 
     
     
       10. The method of claim 1 wherein the concentration of aqueous hydrochloric acid is .1 to 1 N. 
     
     
       11. The method of claim 1 wherein the solution is washed with 30 to 300 parts of ultrapure water per 100 parts by weight of polymer solution. 
     
     
       12. The method of claim 1 wherein the solution is washed with 50 to 100 parts by weight of ultrapure water per 100 parts by weight of polymer solution. 
     
     
       13. The method of claim 1 wherein the solution is washed with 10 to 200 parst by weight of aqueous hydrochloric acid per 100 parts by weight of polymer solution. 
     
     
       14. The method of claim 1 wherein the solution is washed with 30 to 50 parts by weight of aqueous hydrochloric acid per 100 parts by weight of polymer solution.